摘要
Let M be a closed n-manifold of positive sectional curvature. Assume that M admits an effective isometrical T1× Zpk-action with p prime. The main result of the article n+1 for n 〉 5, then there exists a positive constant p(n), is that ifk=lforn=3or k〉 n+1/4 for n≥5,then there exists a positive constant p(n),depending only on n, such that π1 (M) is cyclic if p ≥ p(n).
Let M be a closed n-manifold of positive sectional curvature. Assume that M admits an effective isometrical T1× Zpk-action with p prime. The main result of the article n+1 for n 〉 5, then there exists a positive constant p(n), is that ifk=lforn=3or k〉 n+1/4 for n≥5,then there exists a positive constant p(n),depending only on n, such that π1 (M) is cyclic if p ≥ p(n).
基金
Supported partially by NSFC (10826052,10671018)